Are they healthy? Evidence suggests a few gray areas

HAIR DYES

THE 59-YEAR-OLD California woman had been dyeing her graying hair for years. She'd tear open a package of do-it-yourself auburn, mix it up and apply the solution to her roots. Then she'd wait 20 minutes or so, wash it out and feel 10 years younger.

But one day, minutes after she put the dye on her head, her eyes swelled up and her hands started to itch. Once she'd rinsed her hair and washed her hands, the symptoms subsided. Still, she was concerned enough to switch to another brand. But it, too, caused swelling and itchiness, plus hoarseness, and heart palpitations strong enough to send her to the emergency room. The woman switched to yet another product and had the foresight to buy an over-the-counter antihistamine -- just in case. Although this dye, too, caused an allergic reaction, the antihistamine did the trick and got rid of the swelling and itching.

Heartened, she went back to her original brand -- a very bad idea, she soon found out. She applied the dye and immediately her vision blurred, her face and hands swelled, and she got dizzy and shaky. This time the antihistamine didn't help. She couldn't breathe and passed out. Paramedics, summoned by her son, saved her life with an injection of Adrenalin, a powerful anti-allergy drug. As it turned out, she had a severe and rare allergic reaction -- in response to an obscure chemical formed fleetingly during the hair-dyeing process.

For most of us, getting rid of gray or enhancing our natural shade won't mean a brush with death. But if you are among the millions of adults who dye their hair at home or at the beauty salon (four in 10 women; one in 12 men), there's something you should know: Of all cosmetics on the market, hair dyes are uniquely free of government regulation, thanks to an archaic provision of the law known as "the coal tar exemption."

This legislation dates back to the late 1930s, when hair dyes made from coal tar derivatives were found to cause all sorts of allergic reactions. Had they been subject to the regular Food and Drug Administration cosmetics law, they'd all have been taken off the market. The coal tar industry, however, successfully lobbied Congress to exempt hair dyes from cosmetic regulations, so long as the ingredients were listed on the package along with this warning: "Caution: This product contains ingredients which may cause skin irritation on certain individuals and a preliminary test according to accompanying directions should first be made. This product must not be used for dyeing the eyelashes or eyebrows. To do so may cause blindness."

Although coal tar is no longer used in hair dye, that's still all the cautionary advice you get when you pick up the do-it-yourself box from the drugstore or the supermarket -- and it's all that beauty parlors get on the "professional" hair colorings they use.

All in all, when it comes to hair dye safety, you're pretty much on your own. So, what are the real dangers? Is it worth it to cover up that gray, add some golden highlights or try life as a redhead?

First, the question of allergic reac-tions. These appear mosoften with the hair colorings advertised as "permanent" -- used by about 80 percent of the Americans who dye their hair. These penetrate the hair shaft, so the color stays put for a while. The main thing to worry about is an allergic form of skin irritation called contact dermatitis.

That's why a patch test is recommended with every application. Before you set about dyeing your hair, mix up a bit of the solution, dab the stuff on your arm, cover it up and wait at least 24 hours -- or, if you want to be extra cautious, 48 hours, because some reactions can take that long to show up. When you remove the patch, if there's any hint of redness, don't use the product.

The major culprit is a synthetic organic compound called p-phenylenediamine, found in virtually all permanent colorings. It's one of the two solutions you'll find in a box of permanent dye, along with an oxidizing agent, usually peroxide. Mixed together, the two penetrate the hair shaft and undergo a chemical reaction, resulting in a pigmented molecule that's too big to get out of the shaft. Pigments are added to make different colors, but the darker the shade, the more p-phenylenediamine.

"The chemical interacts with your immune system, which mounts a response to get rid of it," says Arthur P. Bertolino, director of the hair consultation unit at New York University Medical Center. "People will get a rash, redness, scaliness, oozing, sometimes even blistering. Occasionally, someone extremely allergic can lose considerable amounts of hair, or even get scarring."

To this day, the connection between hair dye and cancer remains unsettled. A couple of studies seem to show a tenuous link between permanent hair dye use and leukemia or lymphoma, but they involve small numbers of people and are hardly definitive. But part of a huge study -- of 118,000 nurses -- did appear to rule out a suspected link between hair dye and breast cancer.

Still, when it comes to hair dye and safety, gray areas remain. To be absolutely safe, you'd best stick with the shade nature gave you. But if you do choose to use color, it's wise to minimize your risk -- to allergens or to any other side effects -- by minimizing your exposure.